Unbelievably gripping book written as a series of letters from a woman to her estranged husband. The subject of the letters is her relationship with him, but primarily the subject is their son Kevin--a very troubled young man who shot up his school.
The strange thing about this book is that the subject matter is so very shocking and horrific, which is normally is found more in pulpy, mass market novels, and yet it's written at an incredibly high level, vocabulary-wise and structurally. It's incredibly compelling, and almost like a more literary The Bad Seed by William March. So creepy.
For a nonfiction take on a similar subject, check out Columbine by Dave Cullen.